MOON STEPSNASA scientists say that the footprints left on the moon in 1969 by astronauts Buzz Aldrin and Neil Armstrong will last in their present form for over billion years. The moon has no atmosphere or water, so it can have no wind, rain, or other precipitation. It is the effect of wind and water movement on Earth that wear down or erode features like footprints in rock. The moon receives dust and larger particles such as asteroids and meteors from space. The footprints of the astronauts will not last forever because they will eventually be buried or worn by material falling on the moon. Moon footprint statistics: • depth 0.6 cm, or 0.2 inch • length 24  27 cm (0.240.27 m), or 9  10 inches • maximum foot speed 5 km/hr, 1.5 m/sec, or 3.1 mi/hr, 4.88 ft/sec 1. If other life forms from distant stars come to the Earth’s Moon and find the astronauts’ footprints, what are some things they might conclude from studying the trackways? 2. Using either the graphs or Alexander’s formula calculate the stride distance for the walking speed achieved on the Moon. Moon Stride Length = _______________________ Alexander’s formula: (0.25g^{0.5}) (stride^{1.67}) (hip^{1.17}) = speed g = gravitational acceleration constant Hip height = foot length x 4
3. How does the stride distance on the Moon compare to the stride distance for the same speed on the Earth?
4. The above graphs compare the speeds to the stride distances of an Apollo astronaut. Measure your stride distance in meters and use the Earth graph to find your speed on the Earth, then use that speed and the Moon speed graph to find what your stride distance would be on the Moon. (actually your value would only be correct if you were the same height as the astronaut, but you should be close) Earth Stride Distance = ___________meters Earth Speed = ___________ meters/sec (=moon speed) Moon Stride Distance = ___________ meters
Answers to MOON STEPS 
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